Currently, due to rapid development of an intelligent terminal and a mobile application, mobile data traffic increases dramatically, and consequently, it is increasingly difficult for a live network to meet a requirement of increased data traffic. Therefore, a mobile operator hopes to use a non-cellular network to carry a part of traffic of the live network, to offload traffic of the live network. Interworking between a 3rd Generation Partnership Project (3GPP for short) network and a non-3GPP network, for example, interworking between an LTE network and a wireless local area network (Wireless Local Area Network, WLAN for short), is a current research hot topic.
A traffic offloading method is generally that a node on a radio access network (RAN for short) side triggers user balancing between a 3GPP network and a WLAN network or balancing of multiple bearers or multiple Internet Protocol (IP for short) flows of a user according to a load status and a status of a WLAN AP in a region in which a UE is located.
In the prior art, to implement offloading between a 3GPP network and a WLAN, generally, an uplink detector (UL Detector) function is added to a WLAN AP to detect an uplink signal (UL Sounding) sent by the UE to a cellular network, so as to identify that the UE approaches the WLAN, thereby implementing load balancing between the 3GPP network and the WLAN. However, in this method, an uplink detector (UL Detector) needs to be added to the WLAN AP, which results in increased costs of the WLAN AP.